I have some Gelert boots (don't know if they're Herbert / Tryfan or whatever). Anyway, they're leather. They're waterproof. They're grippy. The only thing I would suggest is that your friend gets a size bigger than normal and adds a nice comfy, squishy insole as the ones supplied are fairly inadequate and you feel the floor (cold, lumps and bumps) fairly quickly.
I'd agree with fernman that, because they're so grippy, the soles won't last too long - would wear down quickly on pavement type surfaces. The leather uppers on mine are still like new but the soles have worn noticeably after not really a lot of walking.
To be honest, for urban walking any old pair of boots would suffice.